Pairing assistance (PA) of health professionals between county hospitals and township health centers is one of the key components of the reform of medical alliances in China to strengthen the development of health workforce in primary health care (PHC). This study aims to examine the effect of PA on healthcare utilization for patients with chronic diseases in rural areas. Two waves of National Health Services Survey (2013 and 2018) were used. A total of 13893 and 22725 rural residents with chronic diseases were included in the 2013 and 2018 waves, respectively. Multiple logistic regressions were used to examine the associations between PA and outpatient and inpatient service utilization in PHC. Chow test was used to examine the difference between PA in two models. Among rural patients with chronic diseases, two-week outpatient visits increased from 22.69% to 27.54%, and annual hospitalization admission increased from 20.72% in 2013 to 25.44%. PA was associated with a significant decrease in outpatient visits (p<0.001) in 2018 after controlling for individual and county characteristics. Patients in PA counties were 1.45 times (95% CI 1.10-1.90) more likely to use PHC outpatient care in 2013, but the difference disappeared in 2018 (OR=0.85, 95% CI 0.71-1.01). PA did not reverse the downward trend in the share of PHC outpatient visits. PA under medical alliances in China provides a potential model for building integrated people-centered health systems for other low- and middle-income countries.